const nat_p : set prop const Empty : set axiom nat_0: nat_p Empty const add_SNo : set set set term + = add_SNo infix + 2281 2280 const eps_ : set set const ordsucc : set set axiom eps_ordsucc_half_add: !x:set.nat_p x -> eps_ (ordsucc x) + eps_ (ordsucc x) = eps_ x axiom eps_0_1: eps_ Empty = ordsucc Empty claim eps_ (ordsucc Empty) + eps_ (ordsucc Empty) = ordsucc Empty